9. Because it puts

smart and presumably productive people towards the work of tax avoidance, rather than something useful. In addition, one of big ways to avoid corporate income tax is to invest overseas with overseas profits rather than repatriating it to the US.

Finally, although corporations overall may pay a lower tax rate, there are many corporations that pay at or near the maximum -- it significantly depends on what business / industry you are in. Want to know why all IT call centers are overseas? Its not just due to the cheaper labor (although that is part of it), its that call center profits have no reasonable method of reducing income taxes.

A much simplified, more uniform tax rate which does not tax repatriated money (like the rest of the world) -- even if much lower -- would be a boon for the economy. That being said, we could probably get away with a 20-25% rate and not change total revenue / tax burden.